HLA-D Antigen Expression and Langerhans' Cell Infiltrates in Thyroid Tumors

Papillary carcinomas (PCs) of thyroid are among the most common but least aggressive human malignancies. The factors explaining the indolence of these tumors are unknown but host-tumor immune interactions may play a role. This study was designed to determine if there is morphologic evidence of these. Frozen tissues collected from 21 PCs, 4 follicular adenomas (FAs), 4 follicular carcinomas (FCs), and 11 nodular hyperplasias (NHs) were stained immunohistochemically for HLA-D antigens, lymphocyte and macrophage markers; results were graded numerically. Paraffin-embedded tumors (35 PCs, 10 FAs, and 10 FCs) were stained for S-100 protein to detect Langerhans' cells (LCs). Diffuse staining for HLA-D antigens and heavy mononuclear infiltrates were found more commonly in PCs compared to follicular neoplasms (FNs) or NHs. No consistent relationship was found between lymphocyte/macrophage infiltrates and expression of HLA-D antigens. The largest number of LCs was in PCs (median 11.8 cells/standard microscopic field [c/smf]), fewer cells were found in FA (3.7 c/smf), and the least in FC (0.05 c/smf). Features of host-tumor interaction including HLA-D expression and infiltrates with lymphocyte macrophages and LC are more strongly expressed in PC than other tumors. This may play a role in explaining their biological behavior.     

Sternal wound infections in patients after coronary artery bypass grafting using bilateral skeletonized internal mammary arteries

OBJECTIVES: This study evaluated the risks of sternal wound infections in patients undergoing myocardial revascularization using bilateral skeletonized internal mammary arteries (IMAs). BACKGROUND: The skeletonized IMA is longer than the pedicled one, thus providing the cardiac surgeon with increased versatility for arterial myocardial revascularization without the use of vein grafts. It is isolated from the chest wall gently with scissors and silver clips, and no cauterization is employed. Preservation of collateral blood supply to the sternum and avoidance of thermal injury enable more rapid healing and decrease the risk of sternal wound infection. METHODS: From April 1996 to August 1997, 545 patients underwent arterial myocardial revascularization using bilateral skeletonized IMAs. The right gastroepiploic artery was used in 100 patients (18%). The average age of the patients was 65 years; 431 (79%) were men and 114 (21%) were women; 179 (33%) were older than 70 years of age; 166 (30%) were diabetics. The average number of grafts was 3.2 per patient. RESULTS: The 30-day operative mortality rate was 2% (n = 11). There were six perioperative infarcts (1.1%) and six strokes (1.1%); 9 patients had sternal infection (1.7%) and 15 (2.8%) had superficial infection. Risk factors for sternal infection were chronic obstructive pulmonary disease and emergency operation. Superficial sternal wound infections were more common in women and in patients with chronic obstructive pulmonary disease, renal failure, or peripheral vascular disease. The 1-year actuarial survival rate was 97%. Two of the six late deaths were not cardiac-related. Late dehiscence occurred in three patients (0.6%). The death rate (early and late) of patients with any sternal complication was higher than that of patients without those complications (33% vs. 2.7%). CONCLUSIONS: Routine arterial myocardial revascularization using bilateral skeletonized IMAs is safe, and postoperative morbidity and mortality rates are low, even in elderly patients and those with diabetes. Chronic obstructive pulmonary disease and emergency operations were found to be associated with an increased risk of sternal infections, and the authors recommend avoiding the use of bilateral skeletonized IMAs in patients with these preoperative risk factors.     

Stentless tricuspid valve replacement

Stentless tricuspid valve replacement was performed in a 21-year-old patient with severe destructive tricuspid valve endocarditis resistant to medical therapy. Postoperative recovery was uneventful. Stentless atrioventricular valves are considered an additional treatment option besides stented valves or homograft implantations for severe right-sided endocarditis. Transvalvular hemodynamics are excellent, and right ventricular function can be preserved by suspending the valve at the papillary muscles.     

Operative treatment of hypertrophic obstructive cardiomyopathy and aortic valve disease in infants

BACKGROUND: The indications for operative intervention for symptomatic hypertrophic obstructive cardiomyopathy (HOCM) in infancy and childhood are not well defined because of the rarity of the lesion. The traditional surgical procedure consists of septal myectomy. In an attempt to further improve the outcome of HOCM associated with concentric left ventricular hypertrophy and aortic valve disease in infancy, we have combined resection of the left ventricular septum and free wall with a Ross-Konno procedure. METHODS: Three infants (aged 3, 4, and 10 months) with HOCM (left ventricular aortic gradients of 75, 95, and 110 mmHg), associated concentric left ventricular hypertrophy, and valvar aortic stenosis (n = 1) or combined valvar aortic stenosis and regurgitation (n = 2) underwent extensive resection of fibroelastosis and subendocardial myocardium of the left ventricular septum and free wall in combination with a Ross-Konno operation. All three patients had marked systolic anterior motion of the mitral valve. The length of the incision into the ventricular septum was 1.8, 2.0, and 2.3 cm. RESULTS: In all three patients this procedure resulted in a marked reduction of width of the left ventricular septum (median 9 mm vs 14 mm preoperatively) and the left ventricular posterior free wall (median 8 mm vs 12 mm preoperatively) and an almost twofold increase of the left ventricular end-diastolic volume (median 13.5 cm3 vs 7.0 cm3 preoperatively). The neo-aortic valve functioned normally. Systolic anterior motion of the anterior leaflet of the mitral valve had completely resolved in two patients and had markedly regressed in the remaining patient. At follow-up of 15, 17, and 26 months, two patients had absence of a left ventricular outflow tract gradient and the third patient had a residual sub-valvar gradient of 15 mmHg. CONCLUSIONS: The reported procedure may be a valuable technique in severe forms of hypertrophic cardiomyopathy associated with aortic valve disease. The operation results in enlargement of the left ventricular stroke volume and improvement of the left ventricular diastolic function, restores aortic valve anatomy and function, and abolishes or decreases systolic anterior motion of the mitral valve.     

Association between large aortic arch atheromas and high-intensity transient signals in elderly stroke patients

BACKGROUND AND PURPOSE: Aortic arch atheromas (AAs) have been shown to be a risk factor for ischemic stroke (IS) in the elderly because of their potential for cerebral embolization. However, the association between AAs and the presence of cerebral microemboli has not been clearly established. The aim of this study was to determine whether large AAs are associated with an increased frequency of high-intensity transient signals (HITS) in elderly patients with IS. METHODS: We performed bitemporal simultaneous HITS monitoring of both middle cerebral arteries in 62 consecutive elderly patients with acute IS (mean age 72.5+/-8.8 years, 65% men). In 16 patients, one or both temporal windows were inadequate; therefore, the analysis of HITS was performed in the remaining 46 patients. All patients underwent omniplane transesophageal echocardiography (TEE), and they had no significant extracranial or intracranial artery disease and no cardiac prosthetic valves. Large AA was defined as > or = 4 mm in thickness. Complex AA was defined as ulcerated or mobile, regardless of plaque thickness. HITS monitoring was performed within 24 hours of TEE and analyzed by an experienced neurologist-sonographer blinded to TEE findings. A 9-dB threshold was chosen to discriminate HITS from background Doppler signal. The HITS counts in the left and in the right middle cerebral arteries were added and reported as a total number of HITS in 30 minutes. RESULTS: HITS were detected in 14 (78%) of 18 patients with large AAs versus 8 (29%) of 28 patients with no or small AAs (odds ratio [OR] 8.8, 95% CI 2.2 to 34.8; P=0. 001). The association was also present in 27 patients with no other cardiac embolic sources, such as atrial fibrillation, patent foramen ovale, spontaneous echo contrast, and thrombus (7 of 10 patients with large AAs versus 3 of 17 patients with small or no AA; OR 10.9, 95% CI 1.7 to 68.5; P=0.013). Complex AAs were associated with a higher frequency of HITS than were noncomplex AAs (6 of 6 patients with complex AAs versus 15 of 39 patients with noncomplex AAs; OR 2. 6, 95% CI 1.7 to 3.9; P=0.005). CONCLUSIONS: HITS are significantly associated with large AAs in elderly stroke patients. This observation may support the causal role of large AAs in IS.     

Leukaemia in the vicinity of two tritium-releasing nuclear facilities: a comparison of the Kruemmel Site, Germany, and the Savannah River Site, South Carolina, USA.

In 1991, an increased rate of childhood leukaemia was reported from the small northern German community of Elbmarsch, which is located on the banks of the River Elbe opposite the Kruemmel nuclear power plant. Owing to the fact that the increase occurred six years after the start-up of the plant, radioactive discharges were suspected as being implicated in the development of the cases. Previous investigations have failed to identify any exposure which might be associated with the cluster. Nonetheless, concern regarding the increased tritium burden in the environment remains. To further assess the impact of tritium releases to the environment upon population cancer rates, the releases and leukaemia rates at the Savannah River site, USA, were compared with the Kruemmel site. Based on the data from 1991 to 1995, the incidence of childhood leukaemia in the vicinity of the Savannah River site was non-significantly less than expected compared with the significantly higher than expected rates close to the German plant. In contrast, tritium releases from the Savannah River site exceed those from the Kruemmel site by several orders of magnitude. The results of this observational study suggest that factors other than environmental tritium releases are associated with the increased number of leukaemia cases near the Kruemmel site.     

Ex-chiral pool synthesis and pharmacological aspects of 3-pyrrolidinylisoxazoles

Employing the dopamine autoreceptor agonist (-)-3-PPP (3) as well as the cholinergic receptor ligands 4 and 5 as lead compounds the 3-pyrrolidinylisoxazoles 2a,b as well as its optical antipodes ent 2a,b were synthesized from (R)-aspartic acid (6) and (S)-aspartic acid (ent-6), respectively. Pharmacological properties of the target compounds were evaluated employing dopamine D2 receptor binding studies and functional experiments on muscarinic M2 receptors.